From fd4f4ace264a91355df46186dd88f566fb451aa5 Mon Sep 17 00:00:00 2001 From: David Härdeman Date: Tue, 23 Jun 2020 11:11:26 +0200 Subject: Move rcon to server-rcon in preparation for separate rcon tool --- server-rcon.c | 375 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 375 insertions(+) create mode 100644 server-rcon.c (limited to 'server-rcon.c') diff --git a/server-rcon.c b/server-rcon.c new file mode 100644 index 0000000..5409b48 --- /dev/null +++ b/server-rcon.c @@ -0,0 +1,375 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "main.h" +#include "uring.h" +#include "server.h" +#include "server-rcon.h" + +struct rcon { + struct server *server; + struct connection conn; + struct uring_task task; + struct uring_task_buf tbuf; +}; + +static int32_t +read_int(char **pos, size_t *len) +{ + uint32_t val; + char *p; + + assert_return(pos && *pos, 0); + + if (len && *len < 4) + return 0; + + p = *pos; + val = ((uint8_t)p[0] << 0); + val += ((uint8_t)p[1] << 8); + val += ((uint8_t)p[2] << 16); + val += ((uint8_t)p[3] << 24); + + *pos += 4; + if (len) + *len -= 4; + + return (int32_t)val; +} + +static void +write_int(char **pos, size_t *len, int32_t orig) +{ + uint32_t val = (uint32_t)orig; + char *p; + + assert_return(pos && *pos); + + p = *pos; + p[0] = (val >> 0) & 0xff; + p[1] = (val >> 8) & 0xff; + p[2] = (val >> 16) & 0xff; + p[3] = (val >> 24) & 0xff; + + *pos += 4; + if (len) + *len += 4; +} + +static void +write_str(char **pos, size_t *len, const char *str) +{ + size_t towrite; + + assert_return(pos && *pos && !empty_str(str)); + + towrite = strlen(str); + memcpy(*pos, str, towrite); + *pos += towrite; + if (len) + *len += towrite; +} + +static void +write_end(char **pos, size_t *len) +{ + char *p; + + assert_return(pos && *pos); + + p = *pos; + p[0] = 0x00; + p[1] = 0x00; + + *pos += 2; + if (len) + *len += 2; +} + +enum rcon_packet_type { + RCON_PACKET_LOGIN = 3, + RCON_PACKET_LOGIN_OK = 2, + RCON_PACKET_LOGIN_FAIL = -1, + RCON_PACKET_COMMAND = 2, + RCON_PACKET_RESPONSE = 0, +}; + +static void +create_packet(struct rcon *rcon, int32_t reqid, + enum rcon_packet_type type, const char *msg) +{ + char *pos; + + assert_return(rcon && !empty_str(msg)); + + /* Body */ + pos = &rcon->tbuf.buf[4]; + rcon->tbuf.len = 4; + write_int(&pos, &rcon->tbuf.len, reqid); + write_int(&pos, &rcon->tbuf.len, type); + write_str(&pos, &rcon->tbuf.len, msg); + write_end(&pos, &rcon->tbuf.len); + + /* Header (length of body) */ + pos = &rcon->tbuf.buf[0]; + write_int(&pos, NULL, rcon->tbuf.len - 4); + + debug(DBG_RCON, "created packet (reqid: %" PRIi32 ", type %" PRIi32 + ", len %zu, payload: %s)", + reqid, type, rcon->tbuf.len, msg); +} + +static int +packet_complete(struct uring_task *task, int res) +{ + char *pos; + size_t len; + int32_t plen; + + assert_return(task, 0); + assert_task_alive_or(DBG_RCON, task, return -EINTR); + + pos = task->tbuf->buf; + len = task->tbuf->len; + if (task->tbuf->len < 14) + return 0; + + plen = read_int(&pos, &len); + debug(DBG_RCON, "reply size: %zu bytes, packet size %" PRIi32, + task->tbuf->len, plen + 4); + + if (task->tbuf->len < plen + 4) + return 0; + else + return 1; +} + +static bool +rcon_read_packet(struct rcon *rcon, int32_t *id, + int32_t *type, char **rmsg) +{ + char *pos; + size_t len; + int32_t plen; + + assert_return(rcon && id && type && rmsg, false); + + pos = rcon->tbuf.buf; + len = rcon->tbuf.len; + plen = read_int(&pos, &len); + *id = read_int(&pos, &len); + *type = read_int(&pos, &len); + *rmsg = NULL; + + if (plen < 10) { + error("invalid packet length: %" PRIi32, plen); + return false; + } + + if (len > 2) { + *rmsg = pos; + pos += len - 2; + len = 2; + } + + if (len < 2) { + error("short message"); + return false; + } + + if (pos[0] != '\0' || pos[1] != '\0') { + error("invalid trailer"); + return false; + } + + debug(DBG_RCON, "response - len: %" PRIi32 ", id: %" PRIi32 + ", type: %" PRIi32 ", msg: %s", + plen, *id, *type, *rmsg); + + return true; +} + +static void +rcon_stop_reply(struct uring_task *task, int res) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + int32_t id; + int32_t type; + char *msg; + + assert_return(task); + assert_task_alive(DBG_RCON, task); + + if (res < 0) { + debug(DBG_RCON, "res: %i", res); + goto out; + } + + debug(DBG_RCON, "packet complete"); + rcon_read_packet(rcon, &id, &type, &msg); + + if (id != 2) { + error("rcon stop failed - reply id (%" PRIi32 ")", id); + goto out; + } else if (type != RCON_PACKET_RESPONSE) { + error("rcon stop failed - reply type (%" PRIi32 ")", type); + goto out; + } + + verbose("rcon stop successful (%s)", msg); + +out: + uring_task_put(&rcon->task); +} + +static void +rcon_stop_sent(struct uring_task *task, int res) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + + assert_return(task); + assert_task_alive(DBG_RCON, task); + + if (res < 0) { + debug(DBG_RCON, "res: %i", res); + uring_task_put(&rcon->task); + return; + } + + debug(DBG_RCON, "stop cmd sent"); + uring_tbuf_read_until(&rcon->task, packet_complete, rcon_stop_reply); +} + +static void +rcon_login_reply(struct uring_task *task, int res) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + int32_t id; + int32_t type; + char *msg; + + assert_return(task); + assert_task_alive(DBG_RCON, task); + + if (res < 0) { + debug(DBG_RCON, "res: %i", res); + goto error; + } + + debug(DBG_RCON, "packet complete"); + rcon_read_packet(rcon, &id, &type, &msg); + + if (id != 1) { + error("rcon login failed - unexpected reply id (%" PRIi32 ")", id); + goto error; + } else if (type == RCON_PACKET_LOGIN_FAIL) { + error("rcon login failed - incorrect password"); + goto error; + } else if (type != RCON_PACKET_LOGIN_OK) { + error("rcon login failed - unexpected reply type (%" PRIi32 ")", type); + goto error; + } + + debug(DBG_RCON, "rcon login successful"); + create_packet(rcon, 2, RCON_PACKET_COMMAND, "stop"); + uring_tbuf_write(&rcon->task, rcon_stop_sent); + return; + +error: + uring_task_put(&rcon->task); +} + +static void +rcon_login_sent(struct uring_task *task, int res) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + + assert_return(task); + assert_task_alive(DBG_RCON, task); + + if (res < 0) { + debug(DBG_RCON, "res: %i", res); + uring_task_put(&rcon->task); + return; + } + + debug(DBG_RCON, "login sent"); + uring_tbuf_read_until(&rcon->task, packet_complete, rcon_login_reply); +} + +static void +rcon_connected_cb(struct connection *conn, bool connected) +{ + struct rcon *rcon = container_of(conn, struct rcon, conn); + + assert_return(conn); + assert_task_alive(DBG_RCON, &rcon->task); + + if (!connected) { + error("rcon connection to remote server (%s) failed", + rcon->server->name); + uring_task_put(&rcon->task); + return; + } + + create_packet(rcon, 1, RCON_PACKET_LOGIN, rcon->server->rcon_password); + uring_tbuf_write(&rcon->task, rcon_login_sent); +} + +static void +rcon_free(struct uring_task *task) +{ + struct rcon *rcon = container_of(task, struct rcon, task); + + assert_return(task); + + debug(DBG_RCON, "task %p, idle %p", task, rcon); + rcon->server->rcon = NULL; + xfree(rcon); +} + +void +rcon_refdump(struct rcon *rcon) +{ + assert_return_silent(rcon); + + uring_task_refdump(&rcon->task); +} + +void +rcon_delete(struct server *server) +{ + assert_return_silent(server->rcon); + + debug(DBG_RCON, "closing fd %i", server->rcon->task.fd); + uring_task_destroy(&server->rcon->task); + server->rcon = NULL; +} + +void +rcon_init(struct server *server) +{ + struct rcon *rcon; + + assert_return(server && !server->rcon && !list_empty(&server->rcons) && !empty_str(server->rcon_password)); + + rcon = zmalloc(sizeof(*rcon)); + if (!rcon) + die("malloc: %m"); + + uring_task_init(&rcon->task, "rcon", &server->task, rcon_free); + uring_task_set_buf(&rcon->task, &rcon->tbuf); + rcon->server = server; + server->rcon = rcon; + + connect_any(&rcon->task, &server->rcons, &rcon->conn, rcon_connected_cb); +} -- cgit v1.2.3